JP5157716B2 - Method for manufacturing universal joint yoke - Google Patents

Description

  The present invention relates to a method for manufacturing a yoke that constitutes a universal joint that connects ends of a pair of rotating shafts that do not exist on the same straight line, and enables transmission of rotational force between the rotating shafts. .

  For example, an automobile steering apparatus is configured by connecting a plurality of rotating shafts such as a steering shaft and an intermediate shaft in series via a universal joint. Conventionally, as a universal joint used in such a case, a universal joint called a cardan joint, in which a pair of yokes are displaceably connected by a cross shaft, has been widely used. In addition, it has been widely practiced to produce a yoke constituting such a universal joint by subjecting a metal plate having sufficient rigidity, such as a steel plate, to plastic working.

  FIG. 12 shows what is described in Patent Document 1 as an example of a universal joint yoke manufactured as described above. The yoke 1 includes a coupling cylindrical portion 2 having a cylindrical shape, a pair of flange portions 3 and 4 formed continuously from both circumferential edges of the coupling cylindrical portion 2, and the distal end of the coupling cylindrical portion 2. A pair of arms 5 and 5 formed continuously from two positions on the opposite sides of the edge in the circumferential direction. Of these, the coupling cylinder portion 2 is a portion into which an end portion of a rotating shaft (not shown) to which the yoke 1 is to be fixed is inserted. A female serration 6 is formed on the inner peripheral surface of the coupling cylinder portion 2, and the female serration 6 is engaged with the male serration formed on the outer peripheral surface of the end portion of the rotating shaft, whereby the yoke 1 And relative rotation between the rotation axis and the rotation shaft can be prevented.

  Further, one of the flange portions 3 and 4 has a flange 7 through which a bolt flange (not shown) is inserted, and the other flange portion 4 has a male screw portion of the bolt. A screw hole 8 concentric with the through-hole 7 for screwing is formed. Further, concentric circular holes 9 and 9 are formed at the distal ends of the both arm portions 5 and 5. When the universal joint is configured by combining the yoke 1 and the cross shaft 10, the bearing cups 11 and 11 are press-fitted into the circular holes 9 and 9. Each of these bearing cups 11 and 11 functions as an outer ring of a radial needle bearing, and couples and supports the cross shaft 10 to the yoke 1 so as to be swingable and displaceable.

  The manufacturing operation of the yoke 1 as described above has been conventionally performed as shown in FIG. First, a first intermediate material 12 having a shape as shown in FIG. 13A is made by punching a metal plate having sufficient rigidity, such as a steel plate, by press working. The first intermediate material 12 includes a long rectangular main plate portion 13 and a pair of tongue pieces 14 and 14 projecting from two intermediate portion positions of one end edge in the width direction of the main plate portion 13. Such a first intermediate material 12 is plastically deformed into a shape as shown in (B) of the same figure by pressing between a pair of press dies to form a second intermediate material 15. Then, as shown in the order of (B) → (C) → (D) in the figure, the intermediate portion in the longitudinal direction of the main plate portion 13 constituting the second intermediate material 15 is bent in two stages. The lengthwise intermediate portion is the coupling cylinder portion 2, the longitudinal end portions of the main plate portion 13 are a pair of flange portions 3, 4, and the tongue portions 14, 14 are a pair. The third intermediate material 16 having the arms 5 and 5 is made. A female serration 6 (FIG. 12) is provided on the inner peripheral surface of the coupling cylinder portion 2 constituting the third intermediate material 16, and a through hole 7 and a screw hole 8 (FIG. 12) are provided on the pair of flange portions 3 and 4. Circular holes 9 and 9 (FIG. 12) are respectively formed at the tip portions of the pair of arm portions 5 and 5 to complete the yoke 1.

  By the way, in the case of the yoke 1 as described above, from the viewpoint of sufficiently ensuring the strength and rigidity of the yoke 1, the thickness of the entire pair of flange portions 3 and 4 is made larger than the thickness of the other portions. It is preferable to employ a structure for increasing the size. Such a structure is obtained, for example, in the manufacturing method of the yoke 1 shown in FIG. 13 described above, in the state (A) or (B), both ends in the length direction of the main plate part 13 (the pair of the above after completion). This can be realized by adding a step of increasing the plate thickness of the flange portions 3 and 4. However, a specific and practical method for increasing the plate thickness has not been conventionally known.

For example, a method described in Patent Document 2 is conventionally known as a method for increasing the thickness of a part of a metal plate material. In the case of the method described in Patent Document 2, first, as shown in FIG. 14 (A) → (B), the edge portion of the metal plate material 17 is bent and raised to the edge portion. Part 18 is formed. Next, as shown in FIG. 5B → C, the bent portion 18 is crushed by an upper and lower mold (not shown) to form a thick portion 19 at the edge portion of the metal plate material 17. Thus, the thickness of the edge portion is increased. However, in the case of the method described in Patent Document 2, it is easy to increase the thickness of a relatively narrow region such as the edge portion of the metal plate material 17 to a desired size. However, it is difficult to increase the plate thickness in a relatively wide area such as the above-described both ends in the length direction of the main plate portion 13 to a desired size. For this reason, it is difficult to employ the method described in Patent Document 2 as a method of increasing the plate thickness at both ends in the length direction of the main plate portion 13.
In addition, there exists the following patent document 3 as a well-known literature relevant to this invention.

JP 2004-223616 A Japanese Patent Laid-Open No. 7-155883 JP-A-3-41220

  In view of the circumstances as described above, the method for manufacturing a universal joint yoke according to the present invention uses an intermediate material made by punching a metal plate as a material to change the thickness of a pair of flange portions to other thicknesses. The present invention was invented to realize a method for producing a yoke having a thickness larger than the thickness of the portion with high accuracy and sufficient accuracy.

The method for manufacturing a universal joint yoke according to the present invention includes firstly punching a metal plate as a raw material, so that an intermediate material having at least a long rectangular main plate portion (for example, the main plate portion and the main plate portion An intermediate material having a pair of tongue pieces projecting from two positions of the middle part of one edge in the width direction is made.
After that, by curving the lengthwise intermediate portion of the main plate portion, this lengthwise intermediate portion is used as a non-cylindrical connecting tube portion constituting the universal joint yoke, and the length direction of the main plate portion Both end portions are respectively formed as a pair of flange portions constituting the universal joint yoke formed continuously from both circumferential edges of the coupling cylinder portion. A pair of arms formed continuously from two positions on the opposite side in the radial direction of the leading edge of the coupling cylinder).
In particular, in the method for manufacturing a universal joint yoke according to the present invention, before the coupling cylinder part is completed, a cushioning force having a predetermined size set for each part is applied to each part of the main plate part. While applying the thickness direction of each of these portions, a compressive force is applied to the main plate portion from both sides in the length direction. By performing such a thickening process, the main plate portion is prevented from buckling based on the compressive force, and the increase amount of the thickness of each portion of the main plate portion is adjusted. And the plate | board thickness of the longitudinal direction both ends of the said main plate part is made to increase to a magnitude | size different from the plate | board thickness of the longitudinal direction intermediate part of this main plate part.

  In carrying out the present invention having such characteristics, for example, the method described in claim 2 can be adopted. In the case of the method described in claim 2, before the thickening process is performed, the lengthwise intermediate part is drawn to the intermediate part in the longitudinal direction of the main plate part, so that the combined cylindrical part after completion of the lengthwise intermediate part is obtained. And deformed into a partially cylindrical shape curved in the same direction. After that, in order to maintain the shape of the intermediate portion in the longitudinal direction, the material flow from both sides of the intermediate portion in the longitudinal direction to the intermediate portion in the longitudinal direction is reliably dammed to the intermediate portion in the longitudinal direction. The above thickening process is performed while applying a cushioning force of a size that can be obtained.

  Moreover, when implementing this invention which has the above characteristics, the method of Claim 3, for example can also be employ | adopted. In the case of the method described in claim 3, the drawing process is performed in which the longitudinal intermediate portion is deformed into a partially cylindrical shape curved in the same direction as the combined cylindrical portion after completion in the longitudinal intermediate portion of the main plate portion. The thickening process is started simultaneously with the start of application or during the drawing process. As a result, the thickness of the main plate portion is the same between the lengthwise both ends and the lengthwise intermediate portion of the main plate portion from the start of the thickening process until the drawing process is completed. Increase in proportion. At the same time, after the drawing process is finished, in order to maintain the shape of the lengthwise intermediate part of the main plate part, the die and the drawing punch used in the drawing process are used, On the other hand, the above-described thickening process is continued while applying a cushioning force large enough to dam the flow of the material from both sides of the longitudinal intermediate portion toward the longitudinal intermediate portion. As a result, the plate thickness at both end portions in the length direction of the main plate portion is increased to a value larger than the plate thickness at the intermediate portion in the length direction of the main plate portion.

  Moreover, when implementing this invention which has the above characteristics, the method of Claim 4 can also be employ | adopted, for example. In the case of the method according to the fourth aspect, the thickening process is performed while applying cushioning forces having different sizes to the intermediate portion in the longitudinal direction of the main plate portion and both side portions thereof. As a result, the plate thickness at the intermediate portion in the longitudinal direction of the main plate portion and the plate thickness at both ends in the longitudinal direction are respectively increased, and the amount of increase in the plate thickness at the intermediate portion in the longitudinal direction and the length thereof are increased. The amount of increase in thickness at both ends in the direction is made different from each other.

Furthermore, when implementing the present invention having the above-described features, for example, the method described in claim 5 can be employed. In the case of the method described in claim 5, the cushioning force applied to each part of the main plate part is determined by applying a cushion member or a drawing punch to each part of the upper surface of the main plate part while the main plate part is placed on the upper surface of the die. Generate based on pressing. Moreover, the force which presses this cushion member or an aperture punch is obtained using the downward displacement force of the press ram which comprises a press machine, without changing direction. On the other hand, the compressive force applied to the main plate portion is generated based on pressing both ends in the length direction of the main plate portion with a pair of thickening punches. Moreover, the force which presses these both thickening punches is obtained by converting the downward displacement force of the said press ram into the displacement force of a horizontal direction.
When the method described in claim 5 is adopted, the increase in the plate thickness of the main plate portion caused by applying a compressive force to the main plate portion is approximately the stroke of the press ram constituting the press machine. Proportional. Therefore, the amount of increase in the plate thickness of the main plate portion can be adjusted by adjusting the die height of the press machine, which is correlated with the stroke of the press ram.

  According to the method for manufacturing a universal joint yoke of the present invention as described above, the thickness of a pair of flange portions is set to other parts by using an intermediate material made by punching a metal plate as a material. A yoke larger than the plate thickness can be manufactured efficiently and with sufficient accuracy.

[First example of embodiment]
1-4 show a first example of an embodiment of the present invention corresponding to claims 1 and 2. The universal joint yoke 1a to be manufactured in this example is similar to the conventional yoke 1 shown in FIG. 12 described above, and has a cylindrical coupling cylinder portion 2a and both circumferential edges of the coupling cylinder portion 2a. A pair of flange portions 3a, 4a continuously formed from a pair of arm portions 5a formed continuously from two positions on the opposite side in the circumferential direction of the tip edge of the coupling tube portion 2a, 5a. Of these, the female serration 6 is formed on the inner peripheral surface of the coupling cylinder portion 2a, the through holes 7 and the screw holes 8 are concentric with the flange portions 3a and 4a, and the distal ends of the arm portions 5a and 5a. Concentric circular holes 9 and 9 are formed respectively. In particular, in the case of the yoke 1a to be manufactured in this example, the plate thicknesses of the flange portions 3a and 4a are made larger than the plate thicknesses of the other portions.

  In the case of this example, when manufacturing the yoke 1a, first, a “punching process” → “drawing” is performed on a steel plate such as a hot rolled mild steel plate such as SPHC, SPHD, SPHE, which is a metal plate. Predetermined processing is performed in the order of “process” → “thickening process” → “arm part forming process” → “bending process”. Hereinafter, the specific contents of these steps will be described in the order described above.

  First, in the “punching step”, the first intermediate material 12a as shown in FIG. 2A is obtained by punching the steel plate by press working. The first intermediate material 12a includes a long rectangular main plate portion 13a and a pair of tongue piece portions 14a and 14a protruding from positions of two intermediate portions of one end edge in the width direction of the main plate portion 13a. In the case of this example, the plate thickness (the thickness of the steel plate) T of the first intermediate material 12a is 6 to 8 mm, the length L of the main plate portion 13a is 130 to 150 mm, and the width W is the same. 30-50 mm.

  Next, in the “drawing step”, as shown in FIGS. 2 (A) → (B) and FIG. 3 (A) → (B), the main plate portion 13a constituting the first intermediate material 12a. A partial cylinder curved in the same direction as the completed combined cylinder portion 2a {FIG. 1 and FIG. 2 (E)} is drawn on the intermediate portion in the longitudinal direction by drawing the longitudinal intermediate portion. The second intermediate material 20 is obtained by forming the shaped throttle portion 21. The radius of curvature of the narrowed portion 21 is slightly larger than the radius of curvature of the combined cylinder portion 2a after completion. The purpose of such a “drawing step” is to bring the first intermediate material 12a closer to the completed shape of the yoke 1a and to the both ends of the main plate portion 13a in the longitudinal direction in the “thickening step” described below. It is possible to easily increase the thickness of only the flange portions 3a and 4a in the completed state, and to reduce the bending amount of the intermediate portion in the longitudinal direction of the main plate portion 13a by a “bending step” described later. In this way, it is to prevent the occurrence of cracks in the intermediate portion in the length direction.

  As shown in FIG. 3, the apparatus (pressing machine) used in the “drawing step” includes a die 22, a holder 23, a pair of side cushion members 24 and 24, and a drawing punch 25. When drawing the intermediate portion in the longitudinal direction of the main plate portion 13a, the first intermediate material 12a is placed on the upper surface of the die 22 as shown in FIG. The outer periphery of the first intermediate material 12a is constrained to position the first intermediate material 12a in the horizontal direction. Further, of the main plate portion 13a constituting the first intermediate material 12a, the upper surfaces of both side portions of the intermediate portion in the longitudinal direction, which is a portion to be drawn, are pressed by the pair of side cushion members 24, 24. In this state, the drawing punching force from above is applied to the intermediate portion in the longitudinal direction of the main plate portion 13a by the drawing punch 25 disposed between the side cushion members 24, 24. Accordingly, as shown in FIGS. 3A to 3B, the main plate portion is formed between the convex portion 26 provided on the lower surface of the drawing punch 25 and the concave portion 27 provided on the upper surface of the die 22. The narrowed portion 21 is formed by plastically deforming the lengthwise intermediate portion 13a (the second intermediate material 20 is obtained).

  Even when the side cushion members 24, 24 are not provided or are provided when performing such drawing processing, the cushioning force (the upper surface of the main plate portion 13a) of the side cushion members 24, 24 is provided. 3), the both sides of the main plate portion 13a in the direction indicated by arrows A and B in FIG. 3 (B). It floats up and becomes V-shaped. Therefore, in this example, in order to prevent the occurrence of such a problem, the initial cushioning force of the side cushions 24, 24 is 14.7 kN (1.5 tonf) or more (for example, 14.7 kN). Is set. In the case of this example, the cushioning force of the both side cushion members 24, 24 is obtained by utilizing the downward displacement force of a press ram (not shown) constituting the press machine without changing the direction (for example, appropriate gas It is obtained by selecting springs, coil springs, etc. and adjusting them to the desired value). After completion of the drawing, the side cushion members 24 and 24 and the drawing punch 25 are raised, and the knock pin 37 provided inside the die 22 is raised to take out the second intermediate material 20. .

  Next, in the “thickening step”, as shown in FIG. 2 (B) → (C) and FIG. 4 (A) → (B), the main plate portion constituting the second intermediate material 20. The third intermediate material 28 is obtained by increasing the plate thickness at both ends in the length direction by applying a thickening process to both ends in the length direction 13a. The purpose of such a “thickening process” is to ensure the necessary amount of axial dimensions of the through holes 7 and the screw holes 8 (FIG. 1) formed in the pair of flange portions 3a, 4a after completion. In addition, the circumferential length of the partial cylindrical surface portion {the portion forming the female serration 6 (FIG. 1)} formed on the inner peripheral surface of the coupling cylinder portion 2a formed in the “bending step” described later is required. The amount is to be secured.

  As shown in FIG. 4, the apparatus (press machine) used in the “thickening step” includes a holder 29, a die 22 a, a center cushion member 30 having the same shape as the drawing punch 25 (see FIG. 3), A pair of side cushion members 24 a and 24 a, a pair of drive cams 31 and 31, a pair of slide cams 32 and 32, and a pair of thickening punches 33 and 33 are provided. When increasing the thickness of both ends of the main plate portion 13a in the length direction, the upper surface of the die 22a installed on the bottom surface of the holder 29, as shown in FIG. The second intermediate material 20 is placed. At the same time, a pair of pressing jigs (not shown) press both side edges of the main plate portion 13a constituting the second intermediate material 20 in the width direction (front and back direction in FIG. 4). Further, the center cushion member 30 presses the upper surface (inner peripheral surface) of the throttle portion 21 which is the middle portion in the length direction of the main plate portion 13 a (the throttle portion 21 is provided on the lower surface of the center cushion 30. The compression portion 26a is compressed and clamped between the convex portion 26a and the concave portion 27a provided on the upper surface of the die 22a. At the same time, the pair of side cushion members 24a and 24a disposed on both sides of the center cushion 30 press both side portions of the throttle portion 21 on the upper surface of the main plate portion 13a.

  In this state, the pair of thickening punches 33 and 33 strongly press both ends in the longitudinal direction of the main plate portion 13a, and by applying a compressive force to both sides of the main plate portion 13a in the length direction, As shown in FIGS. 4A to 4B, only the plate thicknesses at both ends in the length direction of the main plate portion 13a are increased uniformly. In the case of this example, the pair of drive cams 31, 31 that can be displaced in the vertical direction along both inner side surfaces of the holder 29 and the lateral direction in the drawing along the upper surface of the die 22a are possible. The cam mechanism is configured by bringing the pair of slide cams 32 and 32 into contact with each other so that the cam surfaces 34 and 35 are slidable. Then, both the drive cams 31, 31 are pressed downward by a downward displacement force of a press ram (not shown) constituting the press machine, whereby both the above cam surfaces 34, 35 are contacted with each other. The slide cams 32 and 32 can be pressed in a direction approaching each other. Based on the pressing of the back surfaces of the two thickening punches 33, 33 by the two slide cams 32, 32, both longitudinal edges of the main plate portion 13a are formed by the two thickening punches 33, 33. It can be pressed strongly.

  In this example, the compressive force applied to the main plate portion 13a prevents the both end portions in the length direction of the main plate portion 13a from buckling, and the plate thickness at both end portions in the length direction is made uniform. In order to be increased, the initial cushioning force (force for pressing the upper surface of the main plate portion 13a) of the side cushion members 24, 24 is set to 29.4 kN (3 tonf) or more (for example, 29.4 kN). doing. If this cushioning force is set to 19.6 kN (2 tonf) or less, it will not be possible to effectively prevent buckling of both ends in the length direction. On the other hand, if this cushioning force is set to an excessively large value exceeding 19.6 kN, the resistance to thickening increases, and the plate thickness at both ends in the length direction cannot be effectively increased. For this reason, it is preferable that the cushioning force of both the side cushion members 24, 24 is set to be low (for example, about 29.4 kN) within a range exceeding 19.6 kN.

  Further, in the case of this example, the compression portion prevents the throttle portion 21 from buckling, and ensures the flow of material from both ends in the length direction of the main plate portion 13a toward the throttle portion 21. The initial cushion force of the center cushion member 30 (the force for pressing the upper surface of the throttle portion 21) is 235.2 kN (24 tons) or more (for example, so that the shape of the throttle portion 21 can be maintained by damming. 235.2 kN). If the cushioning force is set to 78.4 kN (8 tonf) or less, it becomes impossible to effectively prevent the throttle portion 21 from buckling. For this reason, if only considering preventing the throttle portion 21 from buckling, the cushion force of the center cushion member 30 need only be set larger than 78.4 kN. However, in the case of this example, the cushioning force effectively blocks the material flow from both sides in the length direction of the main plate portion 13a, thereby effectively reducing the thickness of both ends in the length direction of the main plate portion 13a. It needs to be increased. For this reason, the cushioning force of the center cushion member 30 is set to be as large as about 235.2 kN. In the case of this example, the cushion force of the side cushion members 24, 24 and the center cushion member 30 changes the direction of the downward displacement force (press pressing force) of a press ram (not shown) constituting the press machine. (E.g., by selecting appropriate gas springs, coil springs, etc. and adjusting them to a predetermined size). In the case of this example, it is possible to prevent the width of the main plate portion 13a from increasing due to the compressive force, and to effectively increase the plate thickness at both ends in the length direction of the main plate portion 13a. Accordingly, both side edges in the width direction of the main plate portion 13a are pressed so as not to be widened by a pair of holding jigs (not shown).

  In the case of this example, when generating a compressive force to be applied to the main plate portion 13 a, a large reaction force is applied to both inner side surfaces of the holder 29 via the drive cams 31, 31. For this reason, in the case of this example, the holder 29 is made not to be divided but to be integrated, so that the holder 29 can be prevented from being damaged by the reaction force. In the case of this example, the middle part in the width direction of the die 22a is a lifting part 36 that can be lifted and lowered relative to both ends in the width direction. A weak cushioning force is applied to the lower surface of the main plate portion 13a via the lifting / lowering portion 36 by a knock pin 37a provided in the holder 29. After the end of the thickening process, the third intermediate material 28 is taken out by raising the elevating part 36 by the cushion force at the same time that the cushion members 30 and 24 are raised.

  In the “thickening step” as described above, the amount of increase in the plate thickness at both ends in the length direction of the main plate portion 13a is determined by the strokes of the thick punches 33, 33 (and the thick punches 33). There is a correlation with the strokes of the drive cams 31 and 31, the stroke of the press ram (not shown) to which the drive cams 31 and 31 are attached, and the stroke of the press ram. It is roughly proportional to the die height of the press. For this reason, the increase amount of the plate | board thickness of the said length direction both ends can be easily adjusted by adjusting the die height of a press machine.

  Next, in the “arm portion forming step”, as shown in FIGS. 2C to 2D, with respect to the root portions of the pair of tongue pieces 14a and 14a constituting the third intermediate material 28. Each of these root portions is pressed so as to be inclined by a predetermined angle in a direction away from the central axis of the narrowed portion 21 toward the tip side. As a result, a fourth intermediate material 38 is obtained in which the both tongue pieces 14a, 14a are formed as a pair of arms 5a, 5a. The purpose of such an “arm portion forming step” is to form the outer shape of the both arm portions 5a and 5a, and in the “bending step” described below, the side surfaces of both arm portions 5a and 5a are parallel to each other. Facing each other and leaving the appropriate dimensions. In addition, when performing the said press work to the base part of both said tongue piece parts 14a and 14a, these both base parts are extended. For this reason, in order to prevent a crack from being generated along with this extension, it is possible to apply the pressing while applying a compressive force from the distal end side of the tongue portions 14a, 14a. Further, in the above-described “thickening step”, a cushion member for forming the arm portion can be added, and the “thickening step” and the “arm portion forming step” can be combined into one step. If they are combined into one process, the manufacturing cost can be reduced accordingly.

  Next, in the “bending step”, as shown in (D) → (E) of FIG. 2, by further curving the narrowed portion 21 provided on the main plate portion 13 a constituting the fourth intermediate material 38, A fifth intermediate material 39 is obtained. In order to obtain such a fifth intermediate material 39, specifically, a mandrel (not shown) is fitted on the inner diameter side of the throttle portion 21 constituting the fourth intermediate material 38. The shape of the outer peripheral surface of this mandrel is a shape that matches the inner peripheral surface shape (except for the female serration shape) of the completed coupling cylinder portion 2a. In this state, the fourth intermediate material 38 is pushed into a die (not shown). As a result, the intermediate portion in the length direction of the main plate portion 13a constituting the fourth intermediate material 38 is further bent, and both end portions in the length direction of the main plate portion are raised in the bending direction of the throttle portion 21, respectively. . As a result, the narrowed portion 21 is formed as a non-cylindrical connecting tube portion 2a having an inner peripheral surface shape that matches the outer peripheral surface shape of the mandrel, and both end portions in the longitudinal direction of the main plate portion 13a are substantially mutually connected. The pair of parallel flange portions 3 a and 4 a is the fifth intermediate material 39.

  As a measure for preventing cracking when bending the drawn portion 21, the drawn portion 21 is pushed into a die whose radius of curvature is slightly smaller than the radius of curvature of the outer peripheral surface of the drawn portion 21. It is conceivable to perform the bending process of the narrowed portion 21 while applying pressure. Similarly, as another crack prevention measure, it is conceivable to perform the bending process of the drawn portion 21 in two steps. In this case, both ends in the length direction of the main plate portion 13a are raised up to the V-shaped arrangement in the first bending process. Then, in the second bending process, the two end portions in the length direction are raised until they are substantially parallel to each other (while applying a compressive force with a punch from the leading edge of the both end portions in the length direction). Moreover, after the end of the bending process, the mandrel is extracted in the axial direction from the inside of the coupling cylinder portion 2a.

  When the steps shown in FIGS. 2A to 2E as described above are completed, the inner peripheral surface of the coupling cylinder portion 2a constituting the fifth intermediate material 39 is then applied. The female serration 6 is formed with a through hole 7 and a screw hole 8 in the pair of flange portions 3a and 4a, and circular holes 9 and 9 are formed in the tip portions of the pair of arm portions 5a and 5a, respectively. The yoke 1a (FIG. 1) is completed.

  According to the method for manufacturing a universal joint yoke of this example as described above, a pair of flange portions 3a and 4a are used by using the first intermediate material 12a formed by stamping a metal plate as a material. The yoke 1a having a plate thickness larger than that of other portions can be made efficiently and with sufficient accuracy.

[Second Example of Embodiment]
5 to 9 show a second example of an embodiment of the present invention corresponding to claims 1 and 3. In the case of this example, the method of obtaining the third intermediate material 28a shown in FIG. 5B from the first intermediate material 12a shown in FIG. 5A is different from the case of the first example described above. That is, in the case of the first example described above, the first intermediate material 12a shown in FIG. 2A is processed in the “drawing step”, and then the second intermediate shown in FIG. After obtaining the intermediate material 20, the second intermediate material 20 is processed in the “thickening step” to obtain the third intermediate material 28 shown in FIG. On the other hand, in the case of this example, the “drawing / increasing step” in which the “drawing step” and the “thickening step” are combined into one step for the first intermediate material 12a shown in FIG. By applying the “meat process”, the third intermediate material 28a shown in FIG. In the case of this example, the same processing apparatus (press machine) as the above “thickening step” (see FIG. 4) is used in such a “drawing / thickening step”.

  When the “drawing / thickening step” is performed, first, the first intermediate material 12a is set in the processing apparatus, as shown in FIGS. 6A and 7A. In addition, although illustration is omitted, in a state where the press ram to which the pair of side cushion members 24a and 24a are attached is at the top dead end, the elevating part 36 of the die 22a on which the first intermediate material 12a is placed is connected to the knock pin 37a. Due to the weak cushioning force, it floats upward from the position shown in FIG. 6 (A) and FIG. 7 (A). Then, the side cushion members 24a, 24a are displaced downward together with the press ram from the state of being lifted in this way, and the upper surfaces of the portions of the main plate portion 13a near both ends in the length direction are displaced by the side cushion members 24a, 24a. The state in which the elevating part 36 is lowered and seated while pressing is shown in FIGS. 6A and 7A.

If the first intermediate material 12a is set in the processing apparatus as described above, then, in the order of (A) → (B) in FIG. 6, more specifically, (A) → (B) in FIG. As shown in the order of (C) → (D) → (E), the third intermediate material 28a is obtained by subjecting the first intermediate material 12a to the “drawing / thickening process”. Table 1 below shows both the side cushion members 24a, 24a, the center cushion member 30 (drawing punch), and a pair of thickening punches when the “drawing / thickening process” is performed in this manner. The behavior with 33 and 33 is shown. In Table 1 below, “State 1” indicates a state corresponding to (A) in FIG. 6 and FIG. 7 (A), and “State 2” indicates a state corresponding to (B) in FIG. , “State 3” is a state corresponding to FIG. 7C, “state 4” is a state corresponding to FIG. 7D, “state 5” is FIG. The states corresponding to (E) in FIG. 7 are shown.

The meanings of the above states are as follows. First, “State 1” corresponding to FIGS. 6A and 7A shows a state in which the first intermediate material 12a is set in the processing apparatus. In this “state 1”, the upper surfaces of both the side cushion members 24a, 24a hold the upper portions of the main plate portion 13a constituting the first intermediate material 12a closer to both ends in the length direction. Further, both ends of the main plate portion 13a in the width direction (front and back directions in FIGS. 6 to 7) are pressed so as not to be widened by a pair of holding jigs (not shown). In addition, the cushioning force (force for pressing the upper surface of the main plate portion 13a) of the side cushion members 24a, 24a is the same as the cushioning force set in the “thickening step” of the first example described above. . Further, in the “state 1”, the center cushion member 30 and the both thickening punches 33 and 33 are not in contact with the main plate portion 13a (close to each other through a minute gap) or are in contact with each other. Even if it is, it is in a no-load state.

  Next, “State 2” corresponding to FIG. 7B is a state in which the center cushion member 30 starts pushing the intermediate portion in the longitudinal direction of the main plate portion 13a from above, that is, the intermediate portion in the longitudinal direction. This shows a state in which the drawing process is started. As described above, the reason for starting the drawing process before starting the thickening process of the main plate portion 13a by the both thickening punches 33, 33 is to perform the thickening process before starting the drawing process. This is because the lengthwise intermediate portion of the main plate portion 13a may buckle in an unfavorable direction (upward in FIGS. 6 to 7).

  Next, "State 3" corresponding to (C) in FIG. 7 is a state in which the both end edges in the length direction of the main plate portion 13a are started to be pushed by the both thickening punches 33, 33, that is, the main plate portion 13a The state which started the thickening process is shown. In the “state 3”, the drawing process has not been completed yet. Until this drawing process is completed, the plate thickness of the main plate portion 13a is entirely increased (including the drawn portion 21a formed in the middle portion in the longitudinal direction of the main plate portion 13a) by the above-described thickening process. Increase almost uniformly. In this “state 3”, in order to perform the thickening process together with the drawing process, the feeding speed of the both thickening punches 33, 33 is set to the length of the main plate portion 13a associated with the drawing process. It is made larger than the reduction speed of the height dimension.

Next, “State 4” corresponding to FIG. 7D is a state in which the drawing process by the center cushion member 30 is completed and the thickening process by both the thickening punches 33 and 33 is continued. Is shown. When the drawing process is completed, the upper surface (inner peripheral surface) of the drawn portion 21a formed at the intermediate portion in the longitudinal direction of the main plate portion 13a is pressed by the center cushion member 30. At this time, the cushion force of the center cushion member 30 (force to press the upper surface of the throttle portion 21a) is the same as the cushion force set in the “thickening step” of the first example described above. For this reason, after the drawing process is completed, the plate thickness of the drawn portion 21a does not increase in the main plate portion 13a, and only the thickness of the portions existing on both sides of the drawn portion 21a continues to increase. .
Next, in “state 5” corresponding to FIG. 6B and FIG. 7E, the thickening process by both the thickening punches 33 and 33 is finished, and the third intermediate material 28a is obtained. Indicates the state.

  In the above-described “drawing / thickening process”, the amount of increase in the thickness of the drawing portion 21a can be easily adjusted by adjusting the die height of the press. Specifically, first, in each case where the size of the die height of the press is DH (1) and DH (2), the above-mentioned “ Try "drawing / thickening process". Then, the plate thicknesses T (1) and T (2) of the throttle part 21a of the sample product after this trial are measured, and the die height and the plate thickness of the throttle part 21a as shown in FIG. Find the relationship that holds between the two. This relationship is proportional as shown in the figure. The reason for this is that, as shown in FIG. 9, between the “state 3” and “state 4”, the amount of increase in the thickness of the narrowed portion 21a and the amount of movement of both the thickening punches 33, 33 This is because a proportional relationship is established between them. However, in the calculation, such a proportional relationship is established because the thickness of the main plate portion 13a is sufficiently larger than the width dimension of the throttle portion 21a in the length direction of the main plate portion 13a as in this example. Only if it is small. In any case, if the relationship as shown in FIG. 8A is obtained, the desired plate of the diaphragm portion 21a is utilized using this relationship as shown in FIG. From the thickness T (desired), the die height size DH (adjustment) for realizing the plate thickness T (desired) is determined. Therefore, the amount of increase in the plate thickness of the narrowed portion 21a can be adjusted by adjusting the size of the die height by such a method.

  In the case of this example as described above, unlike the case of the first example described above, not only the plate thickness at both ends in the length direction of the main plate portion 13a constituting the third intermediate material 28a, but also the main plate portion 13a. It is also possible to increase the thickness of the narrowed portion 21a formed in the middle portion in the length direction. Moreover, the plate thickness at both ends in the length direction of the main plate portion 13a can be made larger than the plate thickness of the throttle portion 21a. In the case of this example, since the plate thickness of the narrowed portion 21a constituting the third intermediate material 28a is increased, the diaphragm of the fourth intermediate material 38a shown in FIG. The plate thickness of the portion 21a, the plate thickness of the combined cylinder portion 2b of the fifth intermediate material 39a shown in FIG. 5D, and the plate thickness of the combined cylinder portion constituting the completed yoke (not shown) are also described above. This can be made larger than in the case of the first example. Other configurations and operations are the same as those of the first example described above.

[Third example of embodiment]
FIGS. 10-11 has shown the 3rd example of embodiment of this invention corresponding to Claim 1,4. In the case of this example, first, the first intermediate material 12a as shown in FIG. 10A is obtained by the same method as the first example described above. Next, the first intermediate material 12a is subjected to the “one-thickening process”. In this “one-thickening process”, as shown in FIGS. 10A to 10B and FIGS. 11A to 11B, the main plate portion 13a constituting the first intermediate material 12a is formed. Thickening processing is applied to the intermediate part in the longitudinal direction and both end parts, and the thickness of the intermediate part and both end parts is set to a different size for each of these parts (the thickness of the intermediate part <the plate of both end parts The second intermediate material 40 is obtained by increasing the thickness.

  As shown in FIG. 11, the processing apparatus (press machine) used in the “one-thickening process” is the processing apparatus (press machine) used in the “thickening process” (see FIG. 4) of the first example described above. ), But the lower end surface of the center cushion member 30a is a flat surface perpendicular to the center axis of the center cushion member 30a, like the lower end surfaces of the pair of side cushion members 24b and 24b, and the die 22b The difference is that the upper surface is entirely flat. Also, when performing the above-mentioned “one-thickening process”, as in the case of performing the “thickening process” (see FIG. 4) of the first example, first, as shown in FIG. The center cushion member 30a and the side cushion members 24b and 24b hold the upper surfaces of the intermediate portion in the longitudinal direction of the main plate portion 13a constituting the first intermediate material 12a and both side portions thereof. At the same time, a pair of pressing jigs (not shown) press both side edges of the main plate portion 13a in the width direction (front and back direction in FIG. 11) so as not to be widened. In this state, as shown in FIG. 11 (A) → (B), both ends of the main plate portion 13a in the longitudinal direction are strongly pressed by a pair of thickening punches 33, 33, and the main plate portion By applying a compressive force to both sides of the main plate portion 13a, the plate thicknesses of the main plate portion 13a in the length direction intermediate portion and both end portions are set to different sizes for the respective portions (plate thickness of the intermediate portion < Increase the thickness uniformly so that the thickness of both ends is equal.

  Thus, in the case of this example, in order to be able to increase not only the length direction both ends of the main plate portion 13a but also the plate thickness of the middle portion in the length direction by the compression force, The cushioning force of the cushion member 30a (the force for pressing the upper surface of the main plate portion 13a) is set to a value greater than the cushioning force set in the “thickening step” (see FIG. 4) of the first example described above. As much as it can be realized). Furthermore, in the case of this example, in order to increase the amount of increase in the plate thickness at both ends in the length direction of the main plate portion 13a by the compression force, the amount of increase in the plate thickness at the intermediate portion in the length direction is increased. The cushion force of both the side cushion members 24b, 24b is made smaller than the cushion force of the center cushion member 30a.

Although different from the case of this example, the cushioning force of the center cushion member 30a is set to 235.2kN (24tonf) or more, and the cushioning forces of the both side cushion members 24b and 24b are respectively 29.4kN (3tonf). ), The plate thickness of the intermediate portion in the length direction of the main plate portion 13a does not increase, and only the plate thicknesses at both ends in the length direction increase.
Further, when the cushioning force of the center cushion member 30a is made smaller than 235.2kN and the cushioning force of the both side cushion members 24b and 24b is 29.4kN, respectively, as in this example, the main plate portion 13a Not only the plate thickness at both ends in the length direction but also the plate thickness at the middle portion in the length direction (at a rate smaller than the plate thickness at both ends in the length direction) is increased.
Further, although different from the case of this example, if the cushioning force of the side cushion members 24b and 24b is made larger than the cushioning force of the center cushion member 30a, the plate thickness of the intermediate portion in the longitudinal direction of the main plate portion 13a. The amount of increase becomes greater than the amount of increase in plate thickness at both ends in the length direction.
However, in any case, the cushioning force of the center cushion member 30a and the side cushion members 24b and 24b is such that the main plate portion 13a can be prevented from buckling due to the compressive force applied to the main plate portion 13a. To do.

  As described above, by making a difference between the cushioning force of the center cushion member 30a and the cushioning force of the side cushion members 24b and 24b, the length of the main plate portion 13a is increased by an amount corresponding to the difference. A difference can be made between the thickness of the middle portion in the length direction and the thickness of both end portions in the length direction. However, the relationship between the cushioning force and the plate thickness is somewhat complicated, so if you frequently change the cushioning force during the thickening process, use a hydraulic mechanism that makes it easy to change the cushioning force. It is preferable (the same applies to the first and second examples of the embodiment described above).

  In any case, when the “one-thickening process” as described above is completed, then, as shown in FIG. The third intermediate material 41 is obtained by performing the same “arm forming process” as in the first example. Next, as shown in FIG. 10 (C) → (D), the third intermediate material 41 is subjected to the same “bending process” as in the first example described above, so that the fifth intermediate material 41 is processed. The material 39a is obtained. However, in the case of this example, since the partial cylindrical throttle part is not formed in the longitudinal direction intermediate part of the main plate part 13a constituting the third intermediate material 41, when performing the "bending step" As a countermeasure for preventing cracking, it is preferable to employ the method of performing the bending process in two steps as described in the first example. Other configurations and operations are the same as those of the first example described above.

  In each of the above-described embodiments, a yoke that is integrally formed of a single metal plate as the yoke 1a shown in FIG. However, in the present invention, for example, as described in Patent Document 3, a front half portion having a pair of arm portions and a base half portion having a coupling cylinder portion and a pair of flange portions are mutually connected. Of the yokes that are coupled and fixed, this base half can also be implemented as a manufacturing object.

BRIEF DESCRIPTION OF THE DRAWINGS The yoke used as the manufacture object of the 1st example of embodiment of this invention is shown, (A) is a top view, (B) is the figure seen from the right side of (A), (C) is (A). The figure seen from below. The figure which shows the intermediate material produced in each manufacturing process in order of these each manufacturing process. Sectional drawing which shows the implementation condition of a "drawing process". Sectional drawing which shows the implementation condition of a "thickening process". The figure similar to FIG. 2 which shows the 2nd example of embodiment of this invention. Sectional drawing which shows the implementation condition of a "drawing / compression process" simply and only the first and last. Sectional drawing which shows the implementation condition of a "drawing / compression process" including the middle. The diagram for demonstrating the method of determining the magnitude | size of the die height for obtaining desired plate | board thickness using the relationship established between the die height of a press machine and the plate | board thickness of a workpiece. The graph which shows the relationship between the movement amount of a thickening punch, and the increase amount of the plate | board thickness of a throttle part. The figure similar to FIG. 2 which shows the 3rd example of embodiment of this invention. Sectional drawing which shows the implementation condition of a "one shot thickening process". 1 shows an example of a conventionally known yoke, (A) is a plan view, (B) is a sectional view taken along line XX of (A), and (C) is a side view as viewed from below (A). . The figure which shows the intermediate material produced in each manufacturing process in order of these each manufacturing process. Sectional drawing which shows one example of the method of increasing the plate | board thickness of a part of metal plate raw material known conventionally from process order.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a Yoke 2, 2a, 2b Coupling cylinder part 3, 3a Flange part 4, 4a Flange part 5, 5a Arm part 6 Female serration 7 Through hole 8 Screw hole 9 Circular hole 10 Cross shaft 11 Bearing cup 12, 12a 1st Intermediate material 13, 13a Main plate part 14, 14a Tongue piece part 15 Second intermediate material 16 Third intermediate material 17 Metal plate material 18 Bending part 19 Thick part 20 Second intermediate material 21, 21a Restricted part 22, 22a, 22b Die 23 Holder 24, 24a, 24b Side cushion member 25 Drawing punch 26, 26a Convex part 27, 27a Concave part 28, 28a Third intermediate material 29 Holder 30, 30a Center cushion member 31 Drive cam 32 Slide cam 33 Thickening punch 34 Cam Surface 35 Cam surface 36 Elevating part 37, 37a Knock pin 38, 38a Fourth intermediate element 39,39a fifth intermediate material 40 second intermediate material 41 a third intermediate material

Claims (5)

  After making an intermediate material with at least a long rectangular main plate by punching the metal plate that is the material, this intermediate portion in the longitudinal direction is curved by bending the intermediate portion in the longitudinal direction of the main plate. And a cylindrical connecting tube portion constituting a universal joint yoke, and both end portions in the length direction of the main plate portion are continuously formed from both circumferential edges of the connecting tube portion, In the method of manufacturing a universal joint yoke, which is a pair of flange portions constituting the universal joint yoke, before the coupling cylinder portion is completed, each portion of the main plate portion is provided for each of these portions. By applying a thickening process that applies a compressive force from both sides in the longitudinal direction to the main plate part while applying a set cushioning force of a predetermined size in the thickness direction of each of these parts, Prevents the main plate from buckling In both cases, while adjusting the amount of increase in the thickness of each portion of the main plate portion, the plate thickness at both ends in the length direction of the main plate portion is set to a size different from the thickness of the intermediate portion in the length direction of the main plate portion. A method of manufacturing a universal joint yoke, characterized in that the yoke is increased.   Before applying the thickening process, the lengthwise intermediate part was deformed into a partially cylindrical shape curved in the same direction as the combined cylinder part after completion by drawing the lengthwise intermediate part of the main plate part. After that, in order to maintain the shape of the intermediate portion in the longitudinal direction, the material flow from both sides of the intermediate portion in the longitudinal direction to the intermediate portion in the longitudinal direction is reliably blocked against the intermediate portion in the longitudinal direction. The method for manufacturing a universal joint yoke according to claim 1, wherein the thickening process is performed while applying a cushioning force of a size that can be obtained.   At the same time as starting the drawing process for deforming the intermediate part in the longitudinal direction of the main plate part into a partial cylindrical shape that is curved in the same direction as the combined cylinder part after completion, or By starting the thickening process from the middle, the thickness of the main plate part is set to the length of both ends of the main plate part in the longitudinal direction until the drawing process is completed after the start of the thickening process. The die used in the drawing and the drawing punch are used to increase the length of the intermediate portion in the longitudinal direction at the same rate and to maintain the shape of the intermediate portion in the longitudinal direction of the main plate after the drawing. The above-mentioned increase is applied to the longitudinal intermediate portion while applying a cushioning force large enough to reliably block the flow of material from both sides of the longitudinal intermediate portion toward the longitudinal intermediate portion. By continuing meat processing, the length of the main plate The thickness of the direction both end portions, the main plate than the plate thickness in the longitudinal direction intermediate portion of the increase to a large value, a manufacturing method for a universal joint yoke according to claim 1.   By increasing the thickness of the main plate part in the length direction intermediate part and both side parts while applying cushioning forces of different sizes, the thickness of the main plate part in the length direction intermediate part and the length direction The plate thicknesses at both ends are increased, and the amount of increase in the plate thickness at the intermediate portion in the length direction is made different from the amount of increase in the plate thickness at both ends in the length direction. A method of manufacturing the described universal joint yoke. The cushioning force applied to each portion of the main plate portion is generated based on pressing each portion of the upper surface of the main plate portion with a cushion member or a drawing punch while the main plate portion is placed on the upper surface of the die. The force that presses the cushion member or the squeeze punch is a force that obtains the downward displacement force of the press ram constituting the press machine without changing the direction,
The compressive force applied to the main plate portion is generated based on pressing both ends of the main plate portion in the longitudinal direction with a pair of thickening punches. This is the force obtained by converting the downward displacement force of the press ram into a horizontal displacement force.
The manufacturing method of the yoke for universal joints in any one of Claims 1-4.

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